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Biomedical subjects

F Diaz

Publications and source records attributed to F Diaz.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Surgical treatment of chronic pulmonary embolism using thromboembolectomy under extracorporeal circulation and deep hypothermia--a new approach route. 3 cases].

The authors, who have successfully performed thrombectomy of the pulmonary artery under extracorporeal circulation and deep hypothermia in three patients, wish to draw attention to the principal factors of success. The decision to operate, as accepted by most surgeons, rests on the patient's functional status (stage III or IV) and on the presence of a systolic pulmonary arterial pressure exceeding 50 mmHg. Deep hypothermia combined with circulatory arrest seems to be the best method, as it improves visual control, thereby avoiding damage to the endothelium or fracture of the distal thrombi during thrombectomy. Finally, a new approach route (severing of the superior pulmonary vein, opening of the pulmonary artery and use of Volmar-Sisteron strippers) makes it possible to remove the entire thrombus, thus obtaining an almost normal pressure in the pulmonary artery. In all three patients, the complications that are mostly due to intrabronchial haemorrhage by disruption of the endothelium, fracture of the distal thrombus or pulmonary artery contusion were avoided.

Adult↗
PubMed1989

Twice a cesarean, always a cesarean?

The cesarean delivery rate has quadrupled during the past two decades, resulting in considerable attention focused on alternatives to cesarean birth. One option, vaginal birth after one previous cesarean, has come to be recognized as an acceptable alternative to routine elective repeat cesarean delivery. The purpose of this report was to evaluate whether women with two previous cesareans can safely undergo a trial of labor. Between July 1, 1982 and June 30, 1986, data were collected prospectively on all women with previous cesareans. Those with a known classical incision or a medical or obstetric contraindication to a trial of labor were excluded from an attempted vaginal delivery. During this period, 67,784 patients were delivered, of whom 6250 (9.2%) had had a previous cesarean. Of the 6250 previous-cesarean patients, 1088 (17.4%) had had two previous cesareans; of these, 501 (46%) underwent a trial of labor and 346 (69%) delivered vaginally. Whereas the overall rate of uterine dehiscence was 3%, the rate in those women who attempted a vaginal delivery was 1.8%, versus 4.6% in those who did not. Overall, oxytocin was used in 284 (57%) and was associated with a dehiscence rate of 2.1%, versus 1.4% in the no-oxytocin group. Successful vaginal delivery was related significantly to the use of oxytocin and to a previous vaginal delivery. Trial of labor in patients with two previous cesareans appears to be a reasonable consideration.

Cesarean Section↗
PubMed1988

Surgery of aortic stenosis and lesions of the ascending aorta.

Between 1978 and 1986, 442 aortic valvular replacements were performed for chronic calcified aortic stenosis. In 11 patients (2.5%, seven men and four women) replacement of the ascending aorta was associated with the valvular replacement, because of: seven supra-coronary aneurysms, two aneurysms involving the Valsalva sinuses, and two acute dissections of the ascending aorta. The repair of the ascending aorta consisted in inserting: one patch on one Valsalva sinus, seven supra coronary Dacron prostheses, three valved conduits (according to the Bentall technique). One patient died postoperatively (9%).

Adult↗
PubMed1988

[Replacement of the ascending aorta with reimplantation of coronary vessels. Apropos of 81 cases].

Between 1973 and 1985, 81 patients underwent Bentall's operation. 90 p. 100 of the patients had cystic medionecrosis, but only 24 showed signs of Marfan's syndrome. It must be noted that 12 patients were reoperation cases, 18 were operated upon in an emergency for tamponade (stage V) on acute dissection, and 7 had lesions that involved the aortic arch. The operative procedure was that described by Bentall; Cabrol's modification was used in only 26 patients. The most recent improvements concerned myocardial and (in case of aortic involvement) cerebral protection with an autonomous perfusion of blood at very low temperature. Mortality was low in patients with annulo-aortic ectasia (1 death in 53 cases; 1.8 p. 100) and rose to 34.5 p. 100 (33.3 p. 100 in reoperation cases) in patients with chronic dissection. Evaluation of mortality by stage showed virtually no risk in stages I and II, whereas 4 of the 9 stage IV patients died within the first post-operative month. Late mortality with a mean follow-up of 4 years was 14.2 p. 100; 2 of the 10 deaths were accidental, and 4 of the remaining 8 deaths were due to the anticoagulant therapy (death was precipitated in 2 cases by the presence of a cerebral aneurysm). No case of systemic embolism was observed, and the authors raise the question of whether long-term anticoagulant therapy should be abandoned. None of the patients who underwent Bentall's operation were reoperated upon, whereas 7 out of the 23 patients who had had supracoronary aortic replacement before 1976 had been reoperated upon within a few years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Replacement of the transverse aortic arch during emergency operations for type A acute aortic dissection. Report of 26 cases.

In type A aortic dissection, the intimal disruption is located on or extends to the transverse arch in about 20% of patients. Replacement of the arch may then be necessary to avoid leaving an unresected, acutely dissected aorta and to prevent bleeding, progression of aneurysm, rupture, and ultimately reoperation or death. From 1970 to September 1987, 119 patients were operated on for type A acute dissection. Starting in January 1977, gelatin-resorcin-formaldehyde biologic glue was used in 91 patients to reinforce the dissected tissues at the suture sites. Among these 119 patients, 26 (ages 32 to 76 years) underwent replacement of the transverse aortic arch in addition to replacement of the ascending aorta. In 20 patients cerebral protection was achieved by profound hypothermia (16 degrees to 20 degrees C) associated with circulatory arrest (15 to 40 minutes, mean 27 minutes) during the distal anastomosis. In six patients the carotid arteries were selectively perfused with cold blood (6 degrees C) during moderate core hypothermia (28 degrees C) while cardiopulmonary bypass was discontinued (19 to 34 minutes, mean 25 minutes) to allow the prosthesis to be sutured without the distal aorta being cross-clamped. Moderate hypothermia avoided the long rewarming time necessitated by profound hypothermia. The hospital mortality rate was 34% (9/26). Two of the 20 patients subjected to profound hypothermia and circulatory arrest died during the operation and seven patients died of postoperative complications. No deaths or major complication were observed in the other six patients. Follow-up of the 17 survivors ranges from 3 to 90 months (mean 39). One patient died 6 months after the operation of cerebral hemorrhage. One patient is disabled by neurologic sequelae. Fifteen patients are in good clinical condition (New York Heart Association class I or II). Postoperative aortograms in 12 patients, and computed tomographic scans in all, have shown a stable repair of the transverse arch in all survivors but a persisting dissection of the descending aorta in 11 (70%). Growing experience and improving results in emergency operations for type A aortic dissection have led us to extend the replacement of the aorta to the transverse arch whenever necessary. The gelatin-resorcin-formaldehyde glue has proved to be an efficient adjunct. The best cerebral protection was obtained in our experience by carotid perfusion with cold blood during circulatory arrest at moderate core hypothermia.

Acute Disease↗
PubMed1987

Cognitive and neurologic findings in subjects with diffuse white matter lucencies on computed tomographic scan (leuko-araiosis).

As part of a prospective clinicopathologic study, a cohort of 105 "normal" elderly volunteers was investigated with computed tomographic scans, psychometric testing (Extended Scale for Dementia [ESD]) and neurologic examination. Computed tomographic scans were evaluated for the presence or absence of white matter lucencies, termed leuko-araiosis. These are defined as patchy or diffuse areas of decreased attenuation involving only white matter and with no change in adjacent ventricles or sulci. The nine controls with leuko-araiosis had lower scores on the ESD than the 96 controls without leuko-araiosis (mean ESD with leuko-araiosis, 227.1 +/- 14; without leuko-araiosis, 237.1 +/- 8), and the difference remains significant even after adjusting for the possible confounding effects of age, sex, education, and infarct detected on computed tomography. Significant differences were also found comparing subjects with leuko-araiosis and those without in respect to abnormal gait, limb power, plantar response, and the rooting and palmomental reflexes. Leuko-araiosis may represent a marker for early dementia. The pathophysiology of this finding remains uncertain. Our results suggest that white matter abnormalities play a role in the development of intellectual impairment in the elderly.

Aged↗
PubMed1987

Vascular risk factors and leuko-araiosis.

Leuko-araiosis was found in 49 of 140 demented patients compared with 12 out of 110 control subjects. Thirty-one of 95 patients with dementia of the Alzheimer's type had leuko-araiosis. A history of stroke was four times more frequent in patients with leuko-araiosis than in those without leuko-araiosis (17.4% and 4.4%, respectively). It occurred in 25% of controls with leuko-araiosis compared with only 2% of those without leuko-araiosis. Mean systolic blood pressure was associated with leuko-araiosis. No association was found for diastolic blood pressure, myocardial infarction, angina, diabetes, or carotid bruits. On logistic regression analysis, the strong association between dementia and leuko-araiosis was mainly explained by a history of stroke. There are common factors in leuko-araiosis and stroke, but stroke alone does not account for leuko-araiosis.

Aged↗
PubMed1987

Vaginal birth after cesarean.

Allowing a woman with a previous cesarean birth a trial of labor rather than performing an elective repeat cesarean section continues to be a controversial area in obstetrics today. In an effort to evaluate the risks associated with a trial of labor, a prospective investigation was undertaken from July 1, 1982, through June 30, 1984. During the first year of the study, patients with a known vertical scar or more than one prior cesarean birth were excluded from an attempted trial of labor. Beginning July 1, 1983, patients with two prior cesarean births were no longer excluded and were studied prospectively. During this 2-year period, 32,854 patients were delivered of their infants at the Los Angeles County/University of Southern California Medical Center. Of these patients, 2708 (8.2%) had undergone a prior cesarean birth, and 1796 women (66%) underwent a trial of labor. A total of 1465 (81%) of them achieved a vaginal delivery. Successful vaginal delivery by the number of prior cesarean sections was as follows: one, 82%; two, 72%; three, 90%. When contrasted with the group without a trial of labor, the group with a trial of labor had significantly less maternal morbidity. In a comparison of the groups with and without a trial of labor, the incidence of uterine dehiscence (1.9% versus 1.9%) and rupture (0.3% versus 0.5%) was similar. With the application of attempted vaginal delivery in our patients with a previous cesarean birth, we were able to reduce our cesarean delivery rate for this population alone by 54%. In summary, the benefits associated with a trial of labor in the patient with a prior cesarean birth far outweigh the risks. The policy of "once a cesarean section, always a cesarean section" should be abandoned.

Cesarean Section↗
PubMed1987

[Emergency surgical repair of acute aortic arch dissection. Apropos of 14 cases].

Among 70 patients operated upon for acute dissection of the ascending aorta between 1977 and 1984, 14 (age range 40-72 years) benefited from emergency aortic arch repair motivated by the presence in, or extension to, this segment of the portal of entry, or by lesions of the supra-aortic main vessels. The operation was performed under cardiopulmonary bypass in all cases. Cerebral protection was ensured in 9 patients by deep hypothermia alone or with circulatory arrest for a mean period of 5 minutes (7 cases), and in 5 patients by continuous brain perfusion (carotid blood flow 4 ml/kg/min; perfusion pressure 70 mmHg). Repair consisted of ascending aorta replacement combined with gluing of the arch whenever possible, or bevelled resection in the concavity of the arch, or complete aortic arch replacement with reimplantation of the cervico-cerebral vessels when necessary. In every case the gelatin-resorcin-formalin glue was used to reinforce the aortic wall or the areas with sutures. Operative mortality was nil. Hospital mortality was 28.5%. In patients operated upon under deep hypothermia alone or associated with circulatory arrest the main complications were neurological (4 cases) and respiratory (3 cases) disorders; these were responsible for the death of 3 patients. A fourth patient died of mediastinitis. No neurological or respiratory complication occurred in patients who had brain perfusion. The mean follow-up period was 37 months (range 7-84 months). Late mortality was nil. All but one patient (sequelae of paraplegia) are in excellent clinical condition. Post-operative angiography alone or combined with computerized tomography showed satisfactory blood distribution in all cases and no aneurysm formation on the dissected aorta despite a persistent false lumen.

Acute Disease↗
PubMed1987

[Clinical experience with the Saint Jude prosthesis. Results over a period of 7 years].

Between January, 1979 and December, 1985, 193 Saint Jude medical valves (SJM) were implanted in 165 patients (74 male, 91 female) aged from 14 to 78 years (mean age: 49 years). 101 patients underwent aortic valve replacement, 36 had mitral valve replacement and 21 had multiple valve replacement. Fitting with an SJM prosthesis was a primary emergency operation for 15 patients (9%) and a reoperation for 49 patients (31%). A concomitant surgical procedure was carried out in 39 patients (24%). The overall peri-operative mortality rate was 9% (15 patients), this figure falling to 5% (6/112 patients) when emergency surgery and reoperations are excluded. No patient was lost sight of. Mean follow-up was 37 +/- 3 months (range: 4 to 84 months), for a total duration of 413 years/patient. Five patients died of heart disease during the follow-up period, representing a mortality rate of 1.2% per year/patient. The actual survival rate was calculated as 90% at 1 year and 83% at 7 years. During that period 7 thromboembolic accidents occurred among 5 patients (actual rate: 1.7 accident per 100 years/patient). Two mechanical valve desinsertions requiring reoperation were recorded. Altogether, the actuarial rate of patients without any post-operative complication was 88% at 1 year and 65% at 7 years. Functional improvement was dramatic since 94% of survivors are now in class I or II, whilst 67% of patients were in class III or IV prior to surgery. It may be concluded that the mid-term

Actuarial Analysis↗
PubMed1986

[Aneurysm of the aortic arch. Surgical therapy. 60 cases].

Sixty patients with aortic arch aneurysm have been operated upon at the Foch Medico-Surgical Centre between 1964 and 1984. This period can be subdivided into: January, 1964 to December, 1975 (24 cases) and January, 1976 to April, 1984 (36 cases). The technique used (closure by patch or segmental replacement prosthesis) depended on the type of lesion encountered. In most cases, the cardiopulmonary bypass was between the femoral artery and the right atrium. After experimenting with different methods, we now protect the brain by selective cold blood carotid perfusion, using independent circuit and heat-exchanger. Operative mortality was 12% in series I (1964-1975) and 0% in series II (1975-1984) patients. Hospital mortality was 25% in series I and 13% in series II patients. The improvements obtained during the last few years, using cold blood carotid perfusion and circulatory arrest in the lower half of the body, have made it possible to perform open distal anastomoses. This method ensures excellent brain protection and short cardiopulmonary bypass period.

Adult↗
PubMed1986

[A new technic of cerebral protection. Surgery of the aortic arch].

A new technique of cerebral protection during surgery of the aortic arch is described. It is based on electric perfusion of the carotid arteries with low temperature (6 degrees-10 degrees) blood. This requires the adjunction on the cardiopulmonary bypass of an independent heat-exchanger. The first results obtained in 6 patients showed perfect protection of the brain throughout the surgical procedure, with early recovery from anaesthesia and complete absence of neurological sequelae. There were no deaths.

Aorta, Thoracic↗
PubMed1986

The significance of white matter lucencies on CT scan in relation to cognitive impairment.

As part of a prospective clinicopathological study a cohort of "normal" elderly volunteers (n = 110) has been investigated with CT scans, psychometric testing (Extended Scale for Dementia) and neurological examination. CT scans were evaluated by a neuroradiologist for the presence or absence of white matter lucencies (WML). WML were defined as patchy or diffuse areas of decreased attenuation involving only white matter and with no change in adjacent ventricles or sulci. The 12 subjects with WML had lower scores on the ESD than the 98 subjects without WML (mean ESD with WML 229.5 +/- 14; without WML 236.7 +/- 8.6, t-test p less than .01) and the difference remains significant even after adjusting for the possible confounding effects of age (ANCOVA, P less than .043).

Aged↗
PubMed1984

Can neuropsychological tests detect the sites of cerebrovascular stenoses and occlusions?

Conventional neuropsychological data may not mirror the site of cerebrovascular stenosis in a patient with mild to moderate symptoms. In this study, three groups of cerebral revascularization candidates failed to differ on an extended Halstead-Reitan battery: patients with symptoms and angiographic results referable to the carotid arterial system, subjects with clinical signs and neuroradiological findings referable to the vertebrobasilar arterial system, and patients with symptoms of cerebral ischemia but negative angiograms. Consistent with previous work, these patients generally were mildly impaired on neuropsychological tests, even though many were not symptomatic at the time of assessment. Neuropsychological tests seem to be sensitive to the presence and severity of cerebral ischemia, but in isolation may not be sufficient to determine the loci of vascular stenoses. The incongruence between angiographic and neuropsychological findings underlines the importance of distinguishing among different levels and types of measurements in defining subgroups of cerebral revascularization candidates. Collaboration among neuroscientists will further our understanding of the interrelationships among neurodiagnostic tests.

Carotid Artery Diseases↗
PubMed1982

Ten-year experience of intrapartum fetal monitoring in Los Angeles County/University of Southern California Medical Center.

During the 10-year period from 1970 to 1979, a total of 115,096 deliveries occurred at the Los Angeles County/University of Southern California Medical Center. Of these, 47,567 patients (41.3%) were monitored during labor and delivery. The intrapartum monitoring technique was initially introduced in late 1969. The monitoring rate increased gradually from 18% in 1970 to 74% in 1979. The perinatal mortality rate during this 10-year period was 24.4/1,000. The perinatal mortality rate decreased in an inverse proportion to the monitoring rate. The main portions of the decrease in perinatal mortality rate were in the intrapartum and neonatal death rates. Both the fetal death rate and the neonatal death rate were significantly lower in the monitored patients than in those who were not monitored. This was irrespective of the fact that most high-risk patients were included in the monitored group. The cesarean section rate during this period increased slightly from 9.3% in 1970 to 12.3% in 1979. The primary cesarean section rate increased from 6.4% in 1970 to 8.7% in 1979. These findings suggest the beneficial role of intrapartum fetal monitoring and its association with diminished perinatal losses.

California↗